CVE-2025-37781 i2c: cros-ec-tunnel: defer probe if parent EC is not present
A NULL pointer dereference in the Linux kernel's cros-ec-tunnel driver causes a system crash when the parent EC device is missing.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-37781?
CVE-2025-37781 is a medium-severity vulnerability in Debian Debian Linux, published on 1 May 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
i2c: cros-ec-tunnel: defer probe if parent EC is not present
When i2c-cros-ec-tunnel and the EC driver are built-in, the EC parent device will not be found, leading to NULL pointer dereference.
That can also be reproduced by unbinding the controller driver and then loading i2c-cros-ec-tunnel module (or binding the device).
[ 271.991245] BUG: kernel NULL pointer dereference, address: 0000000000000058 [ 271.998215] #PF: supervisor read access in kernel mode [ 272.003351] #PF: error_code(0x0000) - not-present page [ 272.008485] PGD 0 P4D 0 [ 272.011022] Oops: Oops: 0000 [#1] SMP NOPTI [ 272.015207] CPU: 0 UID: 0 PID: 3859 Comm: insmod Tainted: G S 6.15.0-rc1-00004-g44722359ed83 #30 PREEMPT(full) 3c7fb39a552e7d949de2ad921a7d6588d3a4fdc5 [ 272.030312] Tainted: [S]=CPU_OUT_OF_SPEC [ 272.034233] Hardware name: HP Berknip/Berknip, BIOS Google_Berknip.13434.356.0 05/17/2021 [ 272.042400] RIP: 0010:ec_i2c_probe+0x2b/0x1c0 [i2c_cros_ec_tunnel] [ 272.048577] Code: 1f 44 00 00 41 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 05 06 a0 6c e7 48 89 44 24 08 4c 8d 7f 10 48 8b 47 50 4c 8b 60 78 <49> 83 7c 24 58 00 0f 84 2f 01 00 00 48 89 fb be 30 06 00 00 4c 9 [ 272.067317] RSP: 0018:ffffa32082a03940 EFLAGS: 00010282 [ 272.072541] RAX: ffff969580b6a810 RBX: ffff969580b68c10 RCX: 0000000000000000 [ 272.079672] RDX: 0000000000000000 RSI: 0000000000000282 RDI: ffff969580b68c00 [ 272.086804] RBP: 00000000fffffdfb R08: 0000000000000000 R09: 0000000000000000 [ 272.093936] R10: 0000000000000000 R11: ffffffffc0600000 R12: 0000000000000000 [ 272.101067] R13: ffffffffa666fbb8 R14: ffffffffc05b5528 R15: ffff969580b68c10 [ 272.108198] FS: 00007b930906fc40(0000) GS:ffff969603149000(0000) knlGS:0000000000000000 [ 272.116282] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 272.122024] CR2: 0000000000000058 CR3: 000000012631c000 CR4: 00000000003506f0 [ 272.129155] Call Trace: [ 272.131606] <TASK> [ 272.133709] ? acpi_dev_pm_attach+0xdd/0x110 [ 272.137985] platform_probe+0x69/0xa0 [ 272.141652] really_probe+0x152/0x310 [ 272.145318] __driver_probe_device+0x77/0x110 [ 272.149678] driver_probe_device+0x1e/0x190 [ 272.153864] __driver_attach+0x10b/0x1e0 [ 272.157790] ? driver_attach+0x20/0x20 [ 272.161542] bus_for_each_dev+0x107/0x150 [ 272.165553] bus_add_driver+0x15d/0x270 [ 272.169392] driver_register+0x65/0x110 [ 272.173232] ? cleanup_module+0xa80/0xa80 [i2c_cros_ec_tunnel 3a00532f3f4af4a9eade753f86b0f8dd4e4e5698] [ 272.182617] do_one_initcall+0x110/0x350 [ 272.186543] ? security_kernfs_init_security+0x49/0xd0 [ 272.191682] ? __kernfs_new_node+0x1b9/0x240 [ 272.195954] ? security_kernfs_init_security+0x49/0xd0 [ 272.201093] ? __kernfs_new_node+0x1b9/0x240 [ 272.205365] ? kernfs_link_sibling+0x105/0x130 [ 272.209810] ? kernfs_next_descendant_post+0x1c/0xa0 [ 272.214773] ? kernfs_activate+0x57/0x70 [ 272.218699] ? kernfs_add_one+0x118/0x160 [ 272.222710] ? __kernfs_create_file+0x71/0xa0 [ 272.227069] ? sysfs_add_bin_file_mode_ns+0xd6/0x110 [ 272.232033] ? internal_create_group+0x453/0x4a0 [ 272.236651] ? __vunmap_range_noflush+0x214/0x2d0 [ 272.241355] ? __free_frozen_pages+0x1dc/0x420 [ 272.245799] ? free_vmap_area_noflush+0x10a/0x1c0 [ 272.250505] ? load_module+0x1509/0x16f0 [ 272.254431] do_init_module+0x60/0x230 [ 272.258181] __se_sys_finit_module+0x27a/0x370 [ 272.262627] do_syscall_64+0x6a/0xf0 [ 272.266206] ? do_syscall_64+0x76/0xf0 [ 272.269956] ? irqentry_exit_to_user_mode+0x79/0x90 [ 272.274836] entry_SYSCALL_64_after_hwframe+0x55/0x5d [ 272.279887] RIP: 0033:0x7b9309168d39 [ 272.283466] Code: 5b 41 5c 5d c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d af 40 0c 00 f7 d8 64 89 01 8 [ 272.302210] RSP: 002b:00007fff50f1a288 EFLAGS: 00000246 ORIG_RAX: 000 ---truncated---
Weakness: CWE-476
Which versions are affected by CVE-2025-37781?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-37781?
Apply the vendor's patch.
Is CVE-2025-37781 being exploited?
There is no known exploitation of CVE-2025-37781 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2025-37781, DEBIAN-CVE-2025-37781, GHSA-mrq3-qx26-xjxj, ROOT-OS-DEBIAN-12-CVE-2025-37781, ROOT-OS-UBUNTU-2204-CVE-2025-37781, ROOT-OS-UBUNTU-2404-CVE-2025-37781 and 1 more.